Prior to the introduction of air into an internal combustion engine, it is desirable to remove from the air, so far as possible, entrained particulate matter such as dirt, dust, sand, snow, and the like. Air cleaners and precleaners in general use for such purpose promote more efficient combustion and longer engine life.
Air cleaners are normally mounted on or adjacent the carburetors of internal combustion engines. This locates the air cleaners under the hoods or cover structures for the engine. Air intake pipes or stacks are used to carry outside air to the air cleaners. Air precleaners located outside of the hoods are mounted on the stacks to provide for the flow of relatively clean air into the stacks. The air cleaners function to further clean the air before it flows into the engine. Air precleaners which have been devised utilize centrifugal force of air circulating within a chamber to separate clean air from air entrained with particulate matter for introduction of the clean air into the carburetor inlet. For example, see U.S. Pat. No. 3,670,480. Stationary deflection blades disposed in an inlet to the chamber impart circular motion to the air flowing through the chamber to centrifugally separate air entrained with particulate matter from clean air. An impeller assembly is used to push the air entrained with particulate matter out of a discharge from the chamber. Such devices, however, do not take full advantage of air movement produced at the carburetor inlet to power the impeller.